class Car:  
    def __init__(self, make, model, year, odometer=0):  
        self.make = make  
        self.model = model  
        self.year = year  
        self.odometer = odometer  
  
    def get_descriptive_name(self):  
        return f"{self.year} {self.make} {self.model}"  
  
    def get_odometer(self):  
        print(f"This car has {self.odometer} miles on it.")  
  
    def update_odometer(self, new_odometer):  
        if new_odometer >= self.odometer:  
            self.odometer = new_odometer  
        else:  
            print("You can't roll back odometer!")  

class ElectricCar(Car):  
    def __init__(self, make, model, year, battery_size, odometer=0):  
        super().__init__(make, model, year, odometer) 
        self.battery_size = battery_size  
  
    def describe_battery(self):  
        print(f"This car has a {self.battery_size}-kWh battery.")  
  
my_electric_car = ElectricCar("Tesla", "Model S", 2019, 75)  
  
print(my_electric_car.get_descriptive_name())  
 
my_electric_car.describe_battery()
